Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q5/00—Preparations for care of the hair
  • A61Q5/02—Preparations for cleaning the hair
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
  • A01N25/24—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests containing ingredients to enhance the sticking of the active ingredients
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
  • A01N25/26—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests in coated particulate form
  • A01N25/28—Microcapsules or nanocapsules
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
  • A61K8/14—Liposomes; Vesicles
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q17/00—Barrier preparations; Preparations brought into direct contact with the skin for affording protection against external influences, e.g. sunlight, X-rays or other harmful rays, corrosive materials, bacteria or insect stings
  • A61Q17/02—Barrier preparations; Preparations brought into direct contact with the skin for affording protection against external influences, e.g. sunlight, X-rays or other harmful rays, corrosive materials, bacteria or insect stings containing insect repellants

Definitions

• the present invention relates to a method of making a product adhere to a surface.
• active agent or “active product” will be used indiscriminately below to denote the product which it is desired to fix to a surface.
• the main problem encountered is the fact that the active agent delivered by the shampoo or the detergent product, which is rinsed off, is very largely lost, only a tiny fraction remaining fixed to the treated surface. The persistence is therefore low, even if the proportion of active agent in the product is high. The same type of problem can arise if the treated surface is then exposed to the action of rain, for example.
• Microencapsulation is a solution commonly used to prolong the period of availability of an active agent by only releasing it slowly. It is usually effected by forming a polymer shell around the active principle, either by spraying the active agent in the presence of a polymer or by one of the numerous encapsulation methods developed in industry, such as the various techniques of coacervation, atomization and coprecipitation. Liposomes can also be used, but their low stability and their cost prevent them from being used industrially.
• Multilamellar vesicles of “onion-like” structure are understood as meaning multilamellar vesicles of substantially spherical shape which consist of a series of concentric bilayers from the center to the periphery of the vesicles, which is why the term onion-like structure is used by analogy to qualify such structures.
• the vesicles used according to the invention can be obtained in a particularly simple manner by forming a lamellar liquid crystal phase and causing the bilayers formed to rearrange into multilamellar vesicles.
• a process of this type, affording microcapsules of controlled size, is described in international patent application WO 93/19735; said document describes a process which, through the use of a step involving homogeneous shearing of a lamellar liquid crystal phase, makes it possible to prepare microcapsules of controlled size, not only from lipidic surfactants capable of forming liposomes, but also from various anionic or non-ionic surfactants, and proposes the encapsulation of substances, especially biological substances, in these capsules.
• the active product which is to be made to adhere to a surface from a composition is almost totally incorporated inside multilamellar vesicles, which will be indiscriminately called microcapsules, microvesicles or vesicles in the present specification.
• microcapsules are advantageously of substantially spherical shape and consist of concentric lamellae, giving them a structure of the “onion” type.
• the active substance is thus included right inside the microcapsule, generally in its membranes, and, if appropriate, if it is purely hydrophilic, in the water or the interstitial liquid included inside the microcapsule. However, it always forms an integral part of the microcapsule.
• water/surfactant media are generally used to produce the microcapsules of the invention, replacement of the water with a polar solvent, for example glycerol, is in no way excluded.
• a polar solvent for example glycerol
• the technology proposed according to the invention makes it possible to prepare vesicles which have a very high encapsulation yield, especially a yield in excess of 90% and generally very close to 100%. Being easy to use, this technology also makes it possible to prepare large quantities of encapsulated products. In addition, it does not involve an organic cosolvent, so all kinds of industrial applications can be envisaged, particularly in fields where the use of organic solvents is banned. This constitutes a very particular advantage in the cosmetic, pharmaceutical or food industry, where it is sought to avoid as far as possible the use of organic solvents, which are often difficult to remove completely. However, it is also of value in other sectors of industry where the current tendency is to replace organic solvents with aqueous media.
• Another advantage derives from the fact that the use of surfactants imparts a good dispersibility to the formulation, which can be used in liquid form in aqueous dispersion. This feature is particularly advantageous in the case of hydrophobic or water-insoluble molecules, which can be dispersed by virtue of the invention without the need for an organic solvent.
• Cationic agent is understood as meaning a product carrying a positive charge.
• the multilamellar vesicles whose use is claimed in the present patent application make it possible to encapsulate a large number of active agents with a very good yield.
• the composition of the mixture of surfactants making up the membranes of the vesicles can be adapted to the envisaged application and these vesicles can be prepared from all classes of surfactants.
• the treatment may be a cosmetic or hygiene treatment for the human or animal body which is intended especially to increase the persistence of an active agent on the treated part of the body, said treatment involving the application of a cosmetic or hygiene composition in which said active product is incorporated in substantially spherical, multilamellar vesicles, with a diameter of between 0.1 and 100 ⁇ m, consisting of concentric membranes based on at least one surfactant and separated by a solvent medium, said vesicles having an onion-like structure and carrying a positive overall charge.
• the nature of the product to be fixed will depend closely on the surface to be treated and the intended result.
• the microcapsules used according to the invention to bring the product into contact with the surface make it possible, by virtue of their nature and preparative process, to incorporate therein a practically unlimited number of products which it is desired to fix to the surface to be treated.
• This further constitutes a great advantage of the invention, particularly compared with the techniques involving liposomes.
• liposomes can only contain a limited number of encapsulated products.
• the vesicles used according to the invention must have a positive overall charge.
• Said charge can be imparted either by choosing the nature of the surfactants used to manufacture the microcapsules, or by encapsulating an agent of cationic character inside the microcapsule.
• the agent of cationic character imparting the positive charge to said vesicle may consist of one of the surfactants making up the vesicle membranes or, if appropriate, the product which it is desired to fix in the method of the invention, can in no way be ruled out.
• the multilamellar vesicles which can be used according to the invention advantageously contain two surfactants in their membranes.
• the experiments performed by the inventors show that the surfactants forming part of the composition of said vesicles do not necessarily have to be all cationic for the overall charge on the vesicle to be positive and sufficient for assuring the desired fixing.
• the desired overall positive charge and the desired effect are advantageously achieved at cationic surfactant concentrations which represent 0.01 to 10% by weight of the multilamellar vesicle.
• quaternary ammonium compounds in which the counterion can be:
• hydroxylated, saturated or unsaturated alkyl chains having 1 to 20 carbons it being possible for the hydroxyl group to be esterified and it being possible for these chains to be substituted, to originate from defined compounds or to be mixtures derived from natural products,
• amines which can be protonated according to the pH, and amine salts, in which the nitrogen carries the above-mentioned substituents and/or hydrogen, these products being used under conditions where they are cationic;
• betaine or amino acid derivatives under pH conditions which render them cationic, these derivatives optionally being substituted by the above-mentioned groups;
• polyamine derivatives optionally substituted by polyethylene glycol members
• polyamino acids under pH conditions where they are cationic polyethylene imine
• PVP polyvinylpyrrolidone
• copolymers of quaternized polyvinylpyrrolidone and hydrophilic polymers urethane, acrylate, etc.
• polyquatemium compounds which are cationic polymers described in the International Cosmetic Ingredient Dictionary published by the CTFA (Cosmetic, Toiletry and Fragrance Association);
• the multilamellar vesicles of the invention advantageously contain from 0.01% to 10% by weight, preferably from 0.1% to 5% by weight, of said cationic agent, based on the total weight of the vesicle composition.
• the choice of product to be fixed depends closely on the surface to be treated.
• the product to be fixed may consist either of one of the cationic surfactants or of the encapsulated cationic agent, for example a cationic polymer, is not ruled out.
• the product to be fixed may be the polymer itself, which will act both as the cationic agent imparting a positive overall charge to the multilamellar vesicle, and as the product to be fixed.
• the active product can consist of a cationic surfactant, for example a quaternary ammonium compound, which may be used both as a bactericide to treat a surface, and as a constituent of the vesicle membranes.
• a cationic surfactant for example a quaternary ammonium compound
• the scope of the treatments to which the invention relates also extends to topical pharmaceutical or veterinary treatments of human skin or hair as well as animal skin or fur.
• the invention therefore further relates to methods in which it is sought to fix, to the human or animal body, a pharmaceutical composition comprising an active agent incorporated in a pharmaceutically acceptable vehicle. It relates in particular to a pharmaceutical composition for the treatment of the human or animal body in which at least one active agent forms an integral part of microvesicles as described above.
• one of the advantages of the present invention is that it provides a particularly flexible technique for the preparation of compositions incorporating a product which it is desired to fix to a surface.
• compositions for carrying out the method described above, or the pharmaceutical compositions as described above are easily prepared from a lamellar liquid crystal phase based on at least one surfactant comprising a cationic agent and, if appropriate, a product to be fixed or an agent other than said cationic agent, by shearing said lamellar liquid crystal phase to form said vesicles, and then incorporating said vesicles into a suitable medium.
• This medium will of course be chosen according to the intended application of the composition containing the cationic vesicles.
• it may be an aqueous, oily or organic medium.
• the formulation of the multilamellar vesicles will of course be adapted according to the nature of the dispersion medium.
• compositions incorporating the vesicles will advantageously be in the form of aqueous lotions, shampoos, emulsions, gels, oily dispersions, balms, aerosol solutions or formulations for transdermal applications.
• cationic vesicles dispersed in a lipophilic medium Another field of application where it may be advantageous to use cationic vesicles dispersed in a lipophilic medium is that of treatments applied topically to an animal's skin. Such treatments are commonly referred to as “pour-on” treatments and consist in spreading a composition with a topical effect over the animal's fur.
• the cationic component particularly the cationic surfactant or polymer, is introduced into the composition of the lamellar phase before the latter is sheared to form the vesicles. It is therefore co-encapsulated with the active agent, inside the vesicle, and forms an integral part thereof
• the formulation of the surfactants is adapted to take account of the presence of the cationic surfactant and/or cationic polymer.
• water-soluble active agents such as extracts of plants or algae, vitamins, water-soluble proteins, protein hydrolyzate, peptides, ⁇ -hydroxy acids, salicylic acid, caffeine derivatives, and moisturizing products such as glycerol or glycol derivatives; and
• liposoluble active agents such as vegetable and animal oils, synthetic hydrocarbon or silicone oils, essential oils and mixtures thereof, perfumes and flavorings, vitamins and fatty acid derivatives.
• pyrethrin and synthetic pyrethrinoids permethrin and derivatives
• the presence of another product or composition is not always obligatory insofar as this can be the cationic surface-active product which, in one variant of the invention, can act both as the agent imparting the cationic charge and as the product to be fixed according to the invention.
• the formulation of the lamellar phase is such that at least one of the following conditions is met:
• At least one of the surfactants is a cationic surfactant
• a cationic product is incorporated in said lamellar phase.
• the preparative technique consists in a first step in preparing a lamellar liquid crystal phase containing a mixture of the surfactant(s), the polar solvent, which is preferably water, and, if appropriate, the active product or mixture which it is sought to encapsulate, and then in shearing said liquid crystal phase to form the multilamellar vesicles.
• a liquid crystal phase is not a sufficient condition for the subsequent production of a readily dispersible suspension of multilamellar vesicles. It is also necessary to organize this lamellar phase into a compact stack of these vesicles.
• This rearrangement may be effected by applying a homogeneous shearing stress, as described in patent application WO 93/19735.
• This rearrangement may also be effected by varying the particular formulation of the mixture, especially by choosing a mixture of surfactants such that the desired texture, in the form of multilamellar vesicles, forms spontaneously or, failing that, when a simple mechanical stress is applied, for example when the products are mixed, which causes said mechanical stress.
• mixture of surfactants and the respective concentrations of each of the surfactants contained in this mixture will advantageously be chosen so as to give the desired texture.
• the mixture of surfactants used will generally consist of two types of surfactants, the one rather being soluble in water and therefore having a high HLB, and the other rather being soluble in oil and therefore having a relatively low HLB. Furthermore, it will be particularly advantageous for at least one of the surfactants to have a relatively low CMC, preferably of less than 10 ⁇ 5 mol/liter and particularly preferably of less than 10 ⁇ 6 mol/l.
• the proportion by weight of surfactants in the final mixture is generally between 5 and 90% and preferably between 30 and 70%.
• This homogeneous lamellar phase must have a specific texture, i.e. a spatial arrangement of the lamellae which corresponds to an “onion-like” structure, either spontaneously, or on simple mixing, or under the action of a specific shearing stress as described in international patent application WO 93/19735.
• This structure can easily be recognized by those skilled in the art with a polarizing microscope.
• the vesicles of the “solid” type correspond to an organization of the surfactant molecules in the form of a two-dimensional crystal lattice. These vesicles are of anisotropic shape and most frequently take the form of small faceted crystals. In all cases, the size of the vesicles is between 0.1 and 100 ⁇ m. The faceted appearance of these vesicles is not inconsistent with their onion-type multilamellar structure.
• the vesicles are obtained by mixing (conical flask, mechanical stirring) the surfactants and the water at room temperature and then by heating at 60° C., with continued stirring. When the mixture is homogeneous, the heating is stopped but stirring is continued; then, as soon as the temperature has fallen below 45° C., the malathion is added and the mixture is cooled, with stirring.
• Multilamellar microvesicles encapsulating tetramethrin and cypermethrin as insecticides are prepared from the following formulation:
• Polysorbate 60 40 g Sorbitan stearate 5 g Noramium M2SH* 5 g Tetramethrin 5 g Cypermethrin 5 g Water 40 g *dialkyldimethylammonium chloride with alkyl chains derived from tallow, manufactured by CECA.
• the vesicles are obtained by mixing (conical flask, mechanical stirring) the surfactants and the water at room temperature and then by heating at 60° C., with continued stirring. When the mixture is homogeneous, the heating is stopped but stirring is continued; then, as soon as the temperature has fallen below 45° C., the active molecules are added and the mixture is cooled, with stirring.
• the dispersion is in the form of a milk which is very effective against crawling insects.
• the surface fixing effect is utilized for fixing both to the insect and to the ground to give a long-term action.
• Multilamellar microvesicles encapsulating permethrin as an insecticide are prepared from the following formulation:
• Multilamellar microvesicles are prepared from the following formulation:
• This paste is dispersed by the slow addition of water at room temperature, with stirring.
• the final mixture contains 5% of vesicles. Its viscosity can be adjusted by adding a viscosity enhancer, for example Jaguar C13S, at a maximum concentration of 2%.
• a viscosity enhancer for example Jaguar C13S
• the vesicles are visible on the fibers, whether they be made of polyamide, polyester or cotton.
• the vesicles are obtained by mixing (conical flask, mechanical stirring) the surfactants and the water at room temperature and then by heating at 60° C., with continued stirring. When the mixture is homogeneous, the heating is stopped, the perfume is added as soon as the temperature has fallen below 45° C., and the mixture is then cooled, with continued stirring.
• This paste is dispersed by the slow addition of water at room temperature, with stirring.
• the final mixture contains 10% of vesicles. Its viscosity can be adjusted by adding a viscosity enhancer, for example Jaguar C13S, at a maximum concentration of 0.5%.
• a viscosity enhancer for example Jaguar C13S
• This dispersion of “perfumed” vesicles can be used to perfume fabrics in the long term by attaching the vesicles to the textile fiber, the perfume being released slowly. A small amount of this dispersion sprayed onto a fabric imparts a fragrance which persists for several weeks.
• Body deodorants in atomizers are alcoholic solutions of perfume and bactericide. If it is desired to avoid the use of alcohol, essentially in order to avoid the irritating sensation, dispersions in a light silicone oil are used which, when it evaporates following application, gives a sensation of freshness analogous to that obtained with alcohol.
• Multilamellar vesicles according to the invention are prepared from the following formulation:
• the lecithin, the cationic polymer, the bactericide and 50% of the water are first mixed at room temperature to give a homogeneous paste.
• the ethoxylated lauryl alcohol, the perfume and the remainder of the water are added.
• the addition is complete, the mixture is stirred at room temperature until a viscous paste is obtained; this can readily be dispersed in a base for a non-alcoholic deodorant atomizer.
• This base is essentially composed of a light silicone oil to which aluminum salts (perspiration blockers) can be added.
• the vesicles are dispersed at a concentration of 10%, giving a bactericidal strength of 0.3% in the final dispersion.
• This non-aqueous dispersion tends to produce a sediment due to the reduced efficacy of Brownian motion in an oily medium, and needs to be shaken by hand to resuspend the vesicles before use.
• the antiparasitic treatment of livestock is often carried out using a dispersion of active substance in an oily medium, which is poured over the animal's back in a single application.
• the active principle then diffuses over the whole of the animal by capillarity.
• This method commonly called the “pour-on” method, has the advantage of being rapid to apply and of avoiding the inhalation of the active principle, both by the animal and by the person applying the treatment, which would result from spraying.
• the vesicles according to the invention are particularly suitable for the dispersion of an active principle in an oil and hence for the formulation of “pour-on” forms of veterinary active principles.
• the constituents are mixed at room temperature, being introduced in the following order: lecithin, cationic polymer, sorbitan oleate, active principle, water and then mineral oil. A homogeneous paste is obtained.
• This paste can easily be dispersed in a mineral oil at a concentration of 10% to give a dispersion of vesicles encapsulating the active agent, the viscosity being adapted to use by deposition on the animal's back.
• the dispersion needs to be shaken by hand before use in order to produce a perfect suspension.
• the vesicles are prepared from the following formulation:
• This paste disperses readily in castor oil, which is then used to prepare the lipstick base according to a traditional formulation. It is thus possible to introduce up to 10% of vesicles into the lipstick, corresponding to 6% of glycerol, without degrading the cosmetic qualities of the product.

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• 1997
  • 1997-04-14 FR FR9704548A patent/FR2761912B1/fr not_active Expired - Lifetime
• 1998
  • 1998-04-10 DE DE69826256T patent/DE69826256T3/de not_active Expired - Lifetime
  • 1998-04-10 EP EP98920606A patent/EP0975307B2/de not_active Expired - Lifetime
  • 1998-04-10 AU AU73407/98A patent/AU737915B2/en not_active Ceased
  • 1998-04-10 CA CA2285285A patent/CA2285285C/en not_active Expired - Lifetime
  • 1998-04-10 JP JP54355898A patent/JP2002500630A/ja not_active Ceased
  • 1998-04-10 WO PCT/FR1998/000729 patent/WO1998046199A1/fr active IP Right Grant
  • 1998-04-10 US US09/402,458 patent/US6277404B1/en not_active Expired - Lifetime
  • 1998-04-10 ES ES98920606T patent/ES2230690T5/es not_active Expired - Lifetime

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